Google announced that they have updated the verification process for Google Webmaster Tools. The main changes include:
(1) META Tag verification is no longer tied to the email address on file, i.e. you can change your email and it won't de-verify your site.
(2) The HTML file verification process required that you set up your 404 pages properly by returning a proper 404 server status code. The issue was, many webmasters don't do this and come into the forums complaining they cannot verify. So Google gave up and decided to just allow the verification without requiring a proper 404 status code being returned on non-existing pages. Personally, I feel they should have kept it - it helps webmasters configure their site properly in the long run. But this will reduce a headache for Google in the support forums.
(3) The screens and look of the HTML verification process was updated also. Here is the new look:
The issue is, it broke many of the systems that had automatic verification in place. Google confirmed that Google Sites verification process is currently not working. But others are also reporting issues with verifying other sites. Overall, these issues will be addressed and people will be happy again.
Forum discussion at Google Webmaster Help.